Re: [PATCH 2/5] wined3d: Implement SM4 discard in the GLSL shader backend.

[Matteo Bruni]

2015-06-15 14:07 GMT+02:00 Henri Verbeet :
> dlls/wined3d/glsl_shader.c | 35 +++++++++++++++++++++--------------
>  1 file changed, 21 insertions(+), 14 deletions(-)
>
> diff --git a/dlls/wined3d/glsl_shader.c b/dlls/wined3d/glsl_shader.c
> index 5ba246e..eb98ffe 100644
> --- a/dlls/wined3d/glsl_shader.c
> +++ b/dlls/wined3d/glsl_shader.c
> @@ -4704,22 +4704,29 @@ static void shader_glsl_texreg2rgb(const struct wined3d_shader_instruction *ins)
> - If any of the first 3 components are < 0, discard this pixel */
>
> static void shader_glsl_texkill(const struct wined3d_shader_instruction *ins)
>  {
> - struct glsl_dst_param dst_param;
> - if (ins->ctx->reg_maps->shader_version.major >= 4)
> - {
> -
>    struct glsl_src_param src_param;
>
> - /* The argument is a destination parameter, and no writemasks are allowed */
> - shader_glsl_add_dst_param(ins, &ins->dst[0], &dst_param);
> - if (ins->ctx->reg_maps->shader_version.major >= 2)
> -
>    shader_glsl_add_src_param(ins, &ins->src[0], WINED3DSP_WRITEMASK_0, &src_param);
> -
>    shader_addline(ins->ctx->buffer, "if (bool(floatBitsToUint(%s))) discard;\n", src_param.param_str);
> - }
> - else
> {
> -
>    if (ins->ctx->reg_maps->shader_version.major >= 4)
> -
>        FIXME("SM4 discard not implemented.\n");
> -
>    /* 2.0 shaders compare all 4 components in texkill */
> -
>    shader_addline(ins->ctx->buffer, "if (any(lessThan(%s.xyzw, vec4(0.0)))) discard;\n", dst_param.reg_name);
> - } else {
> -
>    /* 1.X shaders only compare the first 3 components, probably due to the nature of the texkill
> -
>     * instruction as a tex* instruction, and phase, which kills all a / w components. Even if all
> -
>     * 4 components are defined, only the first 3 are used
> -
>     */
> -
>    shader_addline(ins->ctx->buffer, "if (any(lessThan(%s.xyz, vec3(0.0)))) discard;\n", dst_param.reg_name);
> -
>    struct glsl_dst_param dst_param;
> -
> -
>    /* The argument is a destination parameter, and no writemasks are allowed */
> -
>    shader_glsl_add_dst_param(ins, &ins->dst[0], &dst_param);
> -
> -
>    /* 2.0 shaders compare all 4 components in texkill. */
> -
>    if (ins->ctx->reg_maps->shader_version.major >= 2)
> -
>        shader_addline(ins->ctx->buffer, "if (any(lessThan(%s.xyzw, vec4(0.0)))) discard;\n", dst_param.reg_name);
> -
>    /* 1.x shaders only compare the first 3 components, probably due to
> -
>     * the nature of the texkill instruction as a tex* instruction, and
> -
>     * phase, which kills all .w components. Even if all 4 components are
> -
>     * defined, only the first 3 are used. */
> -
>    else
> -
>        shader_addline(ins->ctx->buffer, "if (any(lessThan(%s.xyz, vec3(0.0)))) discard;\n", dst_param.reg_name);
> }
>
> }
>
> --
> 2.1.4

FWIW, https://msdn.microsoft.com/en-us/library/windows/desktop/hh446968%28v=vs.85%...
mentions two variants of the discard instruction. Any clue how is that
_z vs _nz part encoded?